S-91113A005 0.115" ID x 0.27" OD ASME B18.21.1 Internal-Tooth Lock Washers

Key Features & Benefits at a Glance

• Superior vibration resistance with internal teeth that bite into mating surfaces, preventing loosening under dynamic loads
• Enhanced corrosion protection through zinc plating, extending service life in industrial environments
• Exceptional hardness rating (Rockwell C44) ensures dimensional stability and maintains locking force under pressure
• Precision dimensional control with 0.115" ID and 0.27" OD for perfect fit with No. 4 screws
• Industry-standard compliance with ASME B18.21.1 guarantees consistent performance and interchangeability
• Environmental regulation adherence through RoHS 3 and REACH compliance for global market acceptance
• Optimized thickness range (0.012-0.018") provides reliable spring action while accommodating surface variations

Professional Applications & Engineering Value

These zinc-plated steel internal tooth lock washers deliver critical vibration-resistant fastening solutions for demanding industrial applications. The internal tooth configuration creates multiple biting points that securely grip both the fastener and workpiece surface, effectively combating rotational loosening caused by machinery vibration, thermal cycling, and dynamic loads. Manufactured from high-strength steel with Rockwell C44 hardness, these washers maintain their spring properties and locking force even under extreme pressure. The zinc plating provides sacrificial corrosion protection, making them ideal for automotive assemblies, heavy equipment, electrical enclosures, and manufacturing machinery where reliable, long-term fastening is essential. Their compliance with ASME B18.21.1 standards ensures consistent performance and dimensional accuracy across production batches.

Specification Summary & Compliance

This No. 4 internal tooth lock washer features precise dimensional specifications including 0.115" internal diameter, 0.27" outer diameter, and thickness ranging from 0.012" to 0.018". Manufactured to ASME B18.21.1 standards for tooth lock washers, these components meet rigorous industry requirements for dimensional accuracy and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental responsibility and unrestricted use in global markets. The internal tooth location provides optimal locking action for No. 4 screw applications in various industrial settings.